A wide variety of absorbent catamenial tampons have long been known in the art. Most currently commercially available tampons are made from a tampon pledget which has been compressed into a substantially cylindrical form. Tampon pledgets of a variety of types and constructions have been described in the art. Prior to compression, the pledget may be rolled, spirally wound, folded, or assembled as a rectangular pad of absorbent material. Tampons made from a generally rectangular pledget of absorbent material have been popular and successful in the market.
Tampons have been constructed from a variety of absorbent materials. Preferred materials for tampons have included rayon and cotton. These materials are particularly useful in tampon construction because of their low cost, good absorbency, and proven effectiveness in such products. Most current commercially available tampons are made of either rayon, cotton, or homogenous blends of the two. One advantage of rayon is that it typically demonstrates a higher rate of absorbency than cotton. Cotton, on the other hand, is more likely than rayon to retain previously absorbed fluids when subjected to external pressure. Tampons constructed of homogenous blends of cotton and rayon have attempted to combine the advantages of both materials.
Additionally, numerous attempts have been made in the art to provide a tampon pledget with a layered structure. For example U.S. Pat. No. 3,610,243 entitled "Reticulated Paper Tampon" and issued Oct. 5, 1971 to Jones, Sr. discloses a tampon made up of a multiplicity of tissue paper layers which have been folded into a multi-layered tampon. The Jones device, however, does not incorporate layers of different material construction in order to combine the benefits of each.
U.S. Pat. No. 3,051,177 issued to Wilson on Aug. 28, 1962 and U.S. Pat. No. 3,079,921 issued to Brecht et al. on Mar. 5, 1963, disclose a two layer structure and a three layer structure, respectively. The layers of the Wilson device consist of an absorbent layer and a permeable cover to protect the absorbent layers. These layers are folded upon themselves several times to form a six-ply pad. The Brecht device discloses a three layer tampon composed of a resilient layer sandwiched between two absorbent layers. All three layers are folded upward to form the tampon.
U.S. Pat. No. 3,371,666 issued to Lewing on Mar. 5, 1968 and U.S. Pat. No. 3,628,534 issued to Donohue on Dec. 21, 1971, each disclose a generally planar tampon made up of a plurality of layers. Both the Lewing and the Donohue devices, however, incorporate cotton layers on the outside of the pledget with layers of superabsorbent material on the inside. The superabsorbent material is a stand alone film in the Donohue device and is distributed on a carrier web in the Lewing device.
While many of the above-described devices and other tampons currently available have been successful and have gained acceptance in the marketplace, the search for an improved absorbent tampon has continued. Each of the above-described devices suffers from certain drawbacks which are addressed by the development of the present invention. For example, the Wilson and Brecht devices both require extensive folding of a layered structure prior to compression, if any, of the tampon pledget. Additionally, neither device uses layers of rayon and cotton to achieve the benefits of the present invention. The Lewing and Donohue devices do not make the most effective use of a layered structure because layers of cotton are located on the outside of the uncompressed pledget, and because the presence of superabsorbent material is needed to achieve the benefits of those devices. Tampons constructed of homogenous blends of rayon and cotton do offer some improvements in fluid retention over those constructed of rayon alone, but the presence of cotton in the blend tends to erode the fluid acquisition rate benefit of the rayon.
A need, therefore, exists for an improved absorbent tampon comprising layers of rayon and cotton which optimizes the performance benefits of each of these materials. Specifically, such a tampon should demonstrate high fluid acquisition rate simultaneously with a high fluid retention capability. The tampon should be inexpensive and easy to manufacture and be constructed in such a manner as to offer performance improvements over blown tampons which employ rayon and cotton in their construction.